Prior to officially running for President, candidates can use state committees to accept donations in excess of federal limits. The state money can't be spent directly on presidential campaigning, but it can be used to lay the groundwork by hiring staff, renting offices and building goodwill by contributing to state and local politicians. As soon as they officially declare - the money is off limits.
Kenneth P. Vogel at The Politico examined the impact of this rule on Massachusetts governor Mitt Romney :
Other candidates have used the strategy but none as effectively as Romney, who raised nearly $7.1 million through committees set up in seven states before Jan. 3. That's when he declared his presidential intentions with the Federal Election Commission and established a presidential fundraising committee. Those filings brought him under federal campaign finance laws and essentially put off limits the $1.9 million left over in his state committees.
Romney's state committees continued to bring in big, apparently coordinated checks from out-of-state donors right up to Election Day and processed more than $550,000 after that. But his campaign rejected the notion that leaving money on the table reflected poorly on its stewardship of donations.
Technically, Romney has three options. He can let the money sit idle while he runs for President (like Bill Richardson did), another person can take control of the money and give it to other candidates, or he can donate it to charity.
Any guess which option he will pick?